After many times of system integration and improvement in the connection and transmission apparatus for computers, universal serial bus (USB) finally becomes a main trend of the specification for computer peripheral interfaces. The USB not only provides conveniences in application of software, such as the mode of plug and play, but also has a transmission rate satisfying the current market demands. Therefore, USB interface has been employed in various applications, such as external storage medium, external playback medium, data transmission between hard disks, etc. Therefore, all the currently electronic products with a calculating system and other consumptive electronic products must have a USB interface to be successfully accepted in the market.
According to prior art, a male USB connector must be plugged in a corresponding female USB connector with a predetermined side of the male USB connector facing downward or upward relative to the female USB connector. This design causes a certain degree of inconvenience to users. For example, for a general desktop computer, the female USB connector is usually provided at a rear side of the computer case, and the user has to bend or knee to locate it before plugging the male USB connector with the correct side thereof facing toward the correct direction. And, for a notebook computer, the female USB connector is usually provided on an outer peripheral edge of the computer. When the female USB connector is provided on a rear edge of the computer, the user still has to try and locate it before plugging the male USB connector.
In view of the current trend of integrating a computer into household appliances, it is certain complex household appliances would finally become the main trend in the market. That is, it is very possible various kinds of connectors of different specifications are provided here and there on the outer surface of these complex household appliances. Thus, it would be much more convenient to have a USB connector that could be plugged in a complex household appliance without the need of checking whether the connector has been correctly plugged.
With so many conveniences provided by it, the USB connector naturally becomes highly competitive among other connectors of different specifications. However, there are many different brands of electronic products in the market, such as FUJI, CANON, PANTEX, SONY, etc., which have their own specific memory card with a unique specification, such as SD (Smart Card), MS (Memory Stick), MMC (Multi-medium Card), etc. A common feature for these different brands of electronic products is a male connector could be plugged in a female connector only with a correct side of the male connector facing toward a correct direction. In other words, a user has to be certain the male connector has been plugged in the female connector with a correct side of the male connector facing upward or downward as specified. It is possible a user carelessly incorrectly plugs the male connector, or the hardware is installed in a manner different from the typical manner to result in damages in hardware.